## 10.7. Extended Regular Expressions

Extended regular expressions were introduced in Section 8.4. The additional metacharacters available in elvis are:

`\+`

  Matches one or more of the preceding regular expressions.

`\?`

  Matches zero or one of the preceding regular expressions.

`\@`

  Matches the word under the cursor.

`\=`

  Indicates where to put the cursor when the text is matched. For instance, `hel\=lo` would put the cursor on the second l in the next occurrence of hello.

`\{...\}`

  Describes an interval expression, such as `x\{1,3\}` to match x, xx, or xxx.

POSIX bracket expressions (character classes, etc.) are not available,[53] nor is alternation with the `|` character or grouping with parentheses.

> [53]Well, in elvis 2.0 they're there, they just don't work. This is fixed in elvis 2.1.

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